Steel.



UNITED STATES PATENT OFFICE.

ROBERT H. ILLINGWORTH, OF NEWARK, NEW JERSEY, ASSIGNOR TO CRUCIBLE STEEL COMPANY OF AMERICA, A CORPORATION OF NEW JERSEY.

STEEL.

Specification of Letters latent.

Patented March. 17, 1908.

Application filed. July 80, 1907. Serial No. 886,257.

To all whom it may cocoa-1a..

Be it known that I, ROBERT H. ILLING- WORTH, residing at Newark, in the county of Essex and State of New Jersey, a citizen of the United States, have invented or discovered certain new and useful Improvements in Steel, of which improvements the following is a specification.

The invention consists in a new and improved composition of steel, which is made to contain nickel, chromium and tungsten, and which has been found to be extremely strongand durable in service.

The nickel may be present in quantities ranging from .50 per cent. to five per cent., by weight, of the product; the chromium from .10 er cent. to five per cent., and the tun sten rom .25 per cent. to three per cent. Wit in these limits the percentages of the substances named may be varied widely without departing from the spirit or scope of the invention. For example, I havefound that steel of approximately .60 per cent. carbon, and containing substantially 2.50 per cent. of nickel, 1.25 er cent. of chromium, and'one per cent. of tungsten shows, after hardening in oil in the well-known manner, a hi h elastic limit and high tensile strength, com ined with high elongation. On the other hand, the percentages of the said added elements may be altered, within the limits generally stated, and as is well-known in the art, to produce asteel which will be selfhardening. I

The invention is not limited in respect of the percentage of carbon which may be present in the steel since it maybe employed with good results in both low-carbon and hi h-carbon steels.

hesteel may be manufacturediby any suitable process, the said added elements being' mixed with the base while the latter is in molten condition. They may be added either in ure metallic form, or alloyed with iron or ot er substances.

It is well-known in the art that many of the effects due to the admixture of tungsten with steel, can be attained to substantially Y sten specified.

I claim as my invention:

1. Steel containing from .50 per cent. to five per cent. of nickel, from .10 er cent. to five per cent. of chromium, and fl cent. to three per cent. of tungsten.

2'. Steelmontaining from two'per cent. to three per cent. of nickel, from one per cent.

to two per cent. of chromium, and from .25

per cent. to one er cent. of tungsten.

3. Steel-contaming 2.50 per cent. of nickel, 1.25 per cent. of chromium, one per cent. of tungsten, and less than one per cent. of carbon, and characterized b h1 h elastic limit, hi h tensile stren th, an hig elongation.

n testimony w ereof, I have hereunto set my hand.

ROBERT 1 1. ILLINGWORTH.

Witnesses:

W. E. CALVERT, R. R. NELSON, W. A'. MQMANUS.

om .25 per 

